Bats

What bats look like

Bats are small mammals, and the species found in Ontario buildings usually weigh only 3 to 20 g with a body 79 to 130 mm long. The fur is grey or brown, the ears are rounded and the face is small and mouse-like. What sets them apart is the wing, a thin membrane of skin stretched between very long finger bones. Bats are the only mammals capable of true flight. At rest they tuck themselves into tight crevices and can squeeze through gaps smaller than a thumb. They roost in tree hollows, rock crevices and buildings, and they hunt flying insects after dusk using echolocation. In flight the movement is fluttering and irregular, not the direct line a bird takes.

Signs you have bats

• Bats leaving at dusk. Watching the roof line around sunset and seeing animals emerge one after another from the same gap is the clearest evidence of a roost.
• Droppings below an opening. Small dark pellets collecting on a wall, sill, deck or attic floor directly under a gap in the soffit or vent.
• Staining around a gap. Dark greasy marks where fur repeatedly brushes the edge of an entry point.
• Squeaking and scratching. Faint high chittering and shuffling in a wall, attic or chimney, loudest in the evening before the colony leaves.
• A sharp ammonia smell. Accumulated droppings and urine in a roost produce a strong odour that gets worse in hot weather.
• A bat inside the living space. A single bat in a room, especially in midsummer, often means young from a roost in the structure have found their way in.

Watching an evening emergence tells you more than any amount of searching indoors.

Why bats come into Ottawa and Toronto homes

Bats are not after food inside a building. They want a warm, dry, undisturbed space to roost, and an attic or soffit cavity holds heat well, which matters a great deal to females raising young. Colonies gather in late spring to form maternity roosts, stay through the summer while the pups grow, and disperse in late summer and early autumn. The openings they use are small. A gap where the soffit meets the roof, a lifted shingle, an unscreened vent, a chimney without a cap, a space behind fascia or loose flashing is enough. Older buildings with settled joints are the usual candidates. Once a roost is established, bats show strong loyalty to the site and return to the same building year after year.

Are bats dangerous?

Bats do not attack people and are not interested in them. They are valuable insect predators and take large numbers of mosquitoes and moths every night. The health concerns are real but specific. Bats in Ontario can carry rabies, and because a bat bite or scratch can be hard to notice, any direct contact, or finding a bat in a room where someone was sleeping or a child was unattended, should be discussed with a doctor or public health right away. Do not handle a bat with bare hands. Accumulated droppings in a long-used roost can also support a fungus associated with respiratory illness, so cleanup needs proper protection. For the building, the damage is mostly contamination. Droppings and urine soak insulation, stain ceilings and produce persistent odour rather than structural harm.

How to keep bats out

• Inspect the roof line for gaps. Check where soffit meets fascia, around chimneys, under lifted shingles and at vent openings.
• Seal small openings with proper sealant, flashing or fine mesh, remembering that bats use gaps far smaller than most other wildlife.
• Screen gable, attic and exhaust vents, and fit a chimney cap designed to keep wildlife out.
• Repair damaged siding, loose trim, worn flashing and separated joints before the spring roosting season.
• Keep windows and doors screened, and close attic hatches and crawl space openings that lead into the living space.
• Have the building checked outside the maternity period, so that any work can be planned for the right time of year.

Timing matters as much as sealing when bats are involved.

How GO! Pest Control treats bats

• Inspection. We survey the roof line, attic and chimney, watch an evening emergence where needed to confirm the roost and entry points, and assess how long the colony has been there.
• Exclusion. Bats in Ontario are a protected species and maternity season matters, so exclusion is carried out at the right time of year rather than whenever the call comes in. We install one-way devices at the active openings and seal the secondary gaps.
• Removal. The colony leaves on its own to feed and cannot get back in, which is the humane method. Bats are not handled or harmed, and flightless young are never sealed inside.
• Follow-up. We return to confirm the roost is empty, remove the one-way devices, seal the openings permanently and recheck the roof line for anything newly opened.
• Advice. We explain the repairs that matter, what should be done about soiled insulation, and what to do if anyone has had direct contact with a bat.

We are licensed, insured and bonded, and we work in homes, apartments, condos and businesses across the Toronto GTA, Ottawa and Hamilton.

Common questions about bats